Tips for using KDFX with the DIGITAL OUTS

Using the Optional Digital Outputs
Digital audio output is available for K2600s that have either the sampling option or the
digital I/O option. Each option gives you different possibilities for digital output configuration.
The sampling option provides 16-bit stereo digital output, via coaxial (XLR) or optical output
jacks that are supplied with the sampling option. The output is routed through the samplers
analog-to-digital converter (ADC). The stereo digital out carries either the K2600s analog Mix
output, or an external analog signal converted to digital. You can choose either SPDIF or AES/
EBU format for the output. You can set the output sample rate at 48, 44.1, 32, or 29.6 KHz, or you
can slave the K2600 to an external clock via one of the stereo digital inputs. These inputs also
enable you to sample digital signals, as described on page 14-8.
The digital I/O option provides 16- or 20-bit eight-channel digital output in Kurzweil’s
proprietary KDS format, via a serial port supplied with the digital I/O option. You’ll need to
connect a Kurzweil DMTi or other KDS-compatible device to the serial port. The digital I/O
option also provides direct stereo digital output (optical or coaxial).
With the digital I/O option, the output sample rate is -fixed at 48 KHz. The digital I/O option
also provides eight channels of KDS-format digital input, which you can route into VAST
programs. See Playback Mode on page 6-26.
If your K2600 has both the sampling option and the digital I/O option, you can route the signal
to the stereo digital outputs either through the sampler, or directly.
K2600 With Sampling Option Only
1. Go to the SampleMode page (in Program, Setup, Quick Access, or Master mode, press the
Sample soft button).
2. Set the value of the Input parameter to Digital. This enables the Format parameter.
3. Set Format as needed. SPDIF is the most common setting; you may want to use AES/EBU
in professional environments.
4. Set Input to Analog to enable the Src and Rate parameters.
5. Set Src as needed. Use Int to send the K2600s analog Mix output to the digital outs (via
the sampler), or use Ext to convert an external analog signal received at either of the
Analog inputs to digital before sending it to the digital outs.
6. If the K2600 is going to be the master (the device controlling the output sample rate), set
the Rate parameter as desired. This results in a constant output sample rate. If you want
an external master to control the K2600s output sample rate, set Input back to Digital,
and connect the master device to one of the stereo digital inputs. Set the value of Cable
accordingly: Coaxial for the XLR input, or Optical for the optical input. Now the K2600
adjusts its output sample rate according to the clock signal received at the stereo digital in.
If you’re using a Coaxial cable and are going from the Kurzweil’s XLR out to an RCA in, be sure
the cable is wired as described in Cables and Input Jacks on page 14-1.
K2600 With Digital I/O Option Only
The K2600s audio output goes to both the stereo digital outs (XLR and optical) and the eight-
channel KDS outs (it goes to the analog outs as well). The stereo output is a copy of the signal
routed to analog out Also if you want the full K2600 output at the stereo digital outs, you’ll
need to make sure that the current studio routes all of its output to out A (on the OUTPUT page
in the Studio Editor, set the value of the Output A parameter to Mix). The eight-channel output
is a copy of the signal routed to analog outs A (Left and Right) through D (Left and Right).
The output sample rate is -fixed at 48KHz. In any situation requiring different sample rates,
you’ll need to use a sample rate converter (like the DMTi). When you need a clock signal to
synchronize two or more instruments, there are two options:
¥ Make the K2600 the master; it cannot be slaved to an external clock signal. Use a sample rate
converter, if necessary, to match the sample rates of your other instruments.
¥ Make another instrument the master. The K2600 won’t respond to the clock signal. Use a
sample rate converter, if necessary, to match the K2600s output rate to the master’s rate.
When you need to slave one or more instruments or devices to an external master clock, the
K2600 is necessarily the master, because it cannot be slaved to an external clock. If you need to use
sample rates other than 48KHz, you’ll need to use the DMTi or another sample-rate converter to
convert the K2600s output to the desired rate.
When you have the digital I/O option, the Effects-mode page includes an additional
parameter DigOut which enables you to switch the digital outputs word length to 16 bits or
20 bits. Most devices support 16-bit, and many support 20-bit.
You may also want to adjust the value of the Dither parameter on the Effects-mode page, to
adjust the digital noise floor.

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